From: H. Nikolaus Schaller <hns@goldelico.com>
Date: Fri, 17 Feb 2017 20:51:19 +0000 (-0800)
Subject: Input: tsc2007 - check for presence and power down tsc2007 during probe
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=934df23171e7c5b71d937104d4957891c39748ff;p=linux.git

Input: tsc2007 - check for presence and power down tsc2007 during probe

1. check if chip is really present and don't succeed if it isn't.
2. if it succeeds, power down the chip until accessed

Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---

diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c
index 5d0cd51c6f41d..a4b7b4c3d27b2 100644
--- a/drivers/input/touchscreen/tsc2007.c
+++ b/drivers/input/touchscreen/tsc2007.c
@@ -455,6 +455,14 @@ static int tsc2007_probe(struct i2c_client *client,
 
 	tsc2007_stop(ts);
 
+	/* power down the chip (TSC2007_SETUP does not ACK on I2C) */
+	err = tsc2007_xfer(ts, PWRDOWN);
+	if (err < 0) {
+		dev_err(&client->dev,
+			"Failed to setup chip: %d\n", err);
+		return err;	/* usually, chip does not respond */
+	}
+
 	err = input_register_device(input_dev);
 	if (err) {
 		dev_err(&client->dev,